No stone unturned: The epidemiology and outcomes of paediatric urolithiasis in Manchester, United Kingdom

International Alliance of Urolithiasis (IAU) guidelines on the management of pediatric urolithiasis

The aim of this study was to construct the sixth in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis (IAU) that by providing a clinical framework for the management of pediatric patients with urolithiasis based on the best available published literature. All recommendations were summarized following a systematic review and assessment of literature in the PubMed database from January 1952 to December 2023. Each generated recommendation was graded using a modified GRADE methodology. Recommendations are agreed upon by Panel Members following review and discussion of the evidence. Guideline recommendations were developed that addressed the following topics: etiology, risk factors, clinical presentation and symptoms, diagnosis, conservative management, surgical interventions, prevention, and follow-up. Similarities in the treatment of primary stone episodes between children and adults, incorporating conservative management and advancements in technology for less invasive stone removal, are evident. Additionally, preventive strategies aiming to reduce recurrence rates, such as ensuring sufficient fluid intake, establishing well-planned dietary adjustments, and selective use pharmacologic therapies will also result in highly successful outcomes in pediatric stone patients. Depending on the severity of metabolic disorders and also anatomical abnormalities, a careful and close follow-up program should inevitably be planned in each pediatric patient to limit the risk of future recurrence rates.

Imaging urolithiasis: complications and interventions in children

Urolithiasis affects people in all age groups, but over the last decades there has been an increasing incidence in children. Typical symptoms include abdominal or flank pain with haematuria; in acute cases dysuria, fever or vomiting also occur. Ultrasound is considered the modality of choice in paediatric urolithiasis because it can be used to identify most clinically relevant stones. Complementary imaging modalities such as conventional radiographs or non-contrast computed tomography should be limited to specific clinical situations. Management of kidney stones includes dietary, pharmacological and urological interventions, depending on stone size, location or type, and the child's condition. With a very high incidence of underlying metabolic abnormalities and significant recurrence rates in paediatric urolithiasis, thorough metabolic evaluation and follow-up examination studies are of utmost importance.

Comparison of Low-Power vs High-Power Holmium lasers in pediatric RIRS outcomes

OBJECTIVES

to compare the outcomes of using low-power (up to 30W) vs high-power (up to 120W) holmium lasers in retrograde intrarenal surgery (RIRS) in children and to analyse if lasering techniques and the use of access sheath have any influence on the outcomes.

METHODS

We retrospectively reviewed data from 9 centres of children who underwent RIRS with holmium laser for the treatment of kidney stones between January 2015 and December 2020. Patients were divided into two groups: high-power and low-power holmium laser. Clinical, perioperative variables and complications were analysed. Outcomes were compared between groups using Student's T-test for continuous variables, and Chi-square and Fisher's exact test for categorical variables. A multivariable logistic regression analysis model was also performed.

RESULTS

314 patients were included. A high-power and low-power holmium laser was used in 97 and 217 patients, respectively. Clinical and demographic variables were comparable between both groups, except for stone size where the low-power group treated larger stones (mean 11.11 mm vs 9.70 mm; p 0.018). In the high-power laser group, a reduction in surgical time was found (mean 64.29 min vs 75.27 min; p 0.018) with a significantly higher stone-free rate (SFR) (mean 81.4% vs 59%; p <0.001). We found no statistical differences in complication rates. The multivariate logistic regression model showed lower SFR in the low-power holmium group, especially with larger (p = 0.011) and multiple stones (p < 0.001).

CONCLUSION

Our real-world pediatric multicenter study favours high-power holmium laser and establishes its safety and efficacy in children.  .

Hydration and Nephrolithiasis in Pediatric Populations: Specificities and Current Recommendations

Renal lithiasis is less frequent in children than in adults; in pediatrics, lithiasis may be caused by genetic abnormalities, infections, and complex uropathies, but the association of urological and metabolic abnormalities is not uncommon. The aim of this study is to provide a synthesis of nephrolithiasis in children and to emphasize the role of hydration in its treatment. As an etiology is reported in 50% of cases, with a genetic origin in 10 to 20%, it is proposed to systematically perform a complete metabolic assessment after the first stone in a child. Recent data in the field reported increased incidence of pediatric urolithiasis notably for calcium oxalate stones. These changes in the epidemiology of stone components may be attributable to metabolic and environmental factors, where hydration seems to play a crucial role. In case of pediatric urolithiasis, whatever its cause, it is of utmost importance to increase water intake around 2 to 3 L/m² per day on average. The objective is to obtain a urine density less than 1010 on a dipstick or below 300 mOsm/L, especially with the first morning urine. Some genetic diseases may even require a more active 24 h over-hydration, e.g., primary hyperoxaluria and cystinuria; in such cases naso-gastric tubes or G-tubes may be proposed. Tap water is adapted for children with urolithiasis, with limited ecological impact and low economical cost. For children with low calcium intake, the use of calcium-rich mineral waters may be discussed in some peculiar cases, even in case of urolithiasis. In contrast, sugar-sweetened beverages are not recommended. In conclusion, even if parents and patients sometimes have the feeling that physicians do not propose "fancy" therapeutic drugs, hydration and nutrition remain cornerstones of the management of pediatric urolithiasis.

Clinical Features and Surgical Outcomes of the Children With Urolithiasis at a Tertiary Care Hospital: First Report From Somalia

INTRODUCTION

There are very few studies regarding pediatric urolithiasis (PU) reported from Africa, and to date, no data have been presented from Somalia. This study evaluated the sociodemographic and radiological characteristics, treatment, and outcome data of the PU patients treated at Somalia's only tertiary care center.

METHOD

The data of all patients diagnosed with urolithiasis during a 6-year period were reviewed. Only pediatric (age <18) urolithiasis patients were included. Demographic parameters, radiological features, stone characteristics, treatment, and outcome data were collected and analyzed.

RESULTS

Overall, 227 (127 male, 100 female) patients were included. The rate of PU was 8.1%. The mean patient age was 12.7 ± 3.2. More than two-thirds of the patients (n = 161, 70.9%) were adolescents. The stones were located in the kidney in 50.7%, the ureter in 33%, and the bladder in 14.5%. Distal ureteral stones (36%) accounted for the majority of ureteral stones, followed by the ureterovesical junction (26.7%) and proximal ureteral (24%) stones. The mean stone size was 16.2 mm. Most (42.3%) stones had a 10-20 mm diameter, while 23.3% were sized between 6 and 10 mm. Renal insufficiency was present in 5.3%. Among 227 patients, 101 (44.5%) underwent minimally invasive procedures including ureterorenoscopic lithotripsy (n = 40, 18%), retrograde intrarenal surgery (n = 30, 13.2%) and percutaneous nephrolithotomy (n = 31, 14%). Open pyelolithotomy was the most common surgery performed (n = 53, 22.3%). Surgical site infection developed following 3.5% of the open surgery cases. The stone-free rate was 91.3%. It was significantly higher in open cases (98%) compared to the cases performed via a minimally invasive approach (83%) (p = 0.02).

CONCLUSION

In Somalia, PU is more common than in many other countries. Open surgery continues to be the primary treatment modality for children with urolithiasis due to the restricted endourology resources. However, minimally invasive approaches have evolved over the last years.

Does twinkle artifact truly represent a kidney stone on renal ultrasound?

INTRODUCTION

Nephrolithiasis is detected on ultrasound by the presence of an echogenic focus, posterior acoustic shadowing and/or twinkle artifact (TA). TA has been shown to be highly predictive of nephrolithiasis in adults with renal colic and ureteral stones. We sought to evaluate if TA is reliable for diagnosing nephrolithiasis in the pediatric population.

METHODS

We reviewed renal ultrasound reports indicating presence or absence of TA associated with a single echogenic focus in the kidney or ureter. Exclusion criteria were age >18, multiple echogenic foci or medullary calcinosis, no follow-up, or TA located outside the kidney or ureter. Stone was confirmed either by CT within 3 months of color Doppler ultrasound, visualization on ureteroscopy, or patient report of passing the stone.

RESULTS

Five hundred and ninety-nine ultrasound reports were reviewed and 293 met inclusion criteria. Sixty-nine had diffuse twinkle without echogenic focus and 224 showed TA with single echogenic focus. 135 patients had confirmatory information available (Summary Table). Nephrolithiasis was diagnosed using TA and confirmed on confirmatory studies for 49 ultrasounds. The majority of confirmed stones were in the kidney (n = 40; 82%) and mean size of confirmed stones on ultrasound was 5 mm (range 1.5-10). Sensitivity, specificity, positive predictive value and negative predictive value of TA for detecting nephrolithiasis were 83%, 78%, 74% and 86% respectively.

CONCLUSIONS

Compared to the adult literature, TA in children has lower sensitivity, specificity and positive predictive value, but similar negative predictive value for diagnosing nephrolithiasis. This may be related to renal location and smaller stone size. The presence of TA should be weighed in the setting of other clinical and radiographic evidence of nephrolithiasis.